Rules: Normal Sudoku rules apply. Put the digits 1 to 9 once each into every row, column and box.
Doublers: One cell in each row, column and box is a doubler. The value of a doubler cell is equal to twice its digit. Each of the digits from 1 to 9 appears once in a doubler cell.
Anti-Quads: A digit in a black circle means that none of the four surrounding cells contain that value.
Zipper Lines: Values an equal distance away from the center of a lavender zipper line sum to the value in the centre of the line (marked with a circle).
Links:
SudokuPad: https://sudokupad.app/pch5064ywu
Solution code: Row 5, left to right (9 digits).
yesterday, 10:21 by Snookerfan
Beautiful! Very nice break-in and a bit trickier than 3 stars overall for me. Thanks
on 30. May 2026, 18:36 by Playmaker6174
Lovely and fun puzzle with clever use of the available constraints, I enjoyed the solve overall! :)